Romulus 7 1/4 inch Gauge Live Steam Loco

Published on 14 February 2023 at 10:10

This is Romulus, another one of my steam projects, I guess I did this one about 5 or 6 years ago. I had purchased it as a part built project, the steel boiler was already made, as was the frame and a lot of the motion work. Some of it had been done really well , other bits were not to my taste so would get redone.


Tomulus 7 1/4 inch gauge live steam locomotive

It was the largest loco I had done – it was 7 ¼ inch gauge, which is the largest of the common model engineering gauges, the DVD disc in the photo is there so you get an idea of the size.. Locos in this gauge tend to be very heavy so are hard to move around, a van is a must have at this scale. Fortunately I had a van that I was able to install a length of track in to so I could easily transport it to the local model engineering society's track and offload it without using a crane.

It came with a cab but I didn't like the design of it so set about designing one of my own – I found this much easier on this loco than on the scales I was used to working with.

As I was unsure of the quality of the engineering I started by stripping it down to it's component parts, fortunately most of it was quite well done – the cylinders and most of the motion work was fine although some minor parts had to be remade.


Romulus 7 1/4 inch gauce locomotive boiler instalation


It quickly became apparent that it was going to be hard to work with this thing on the floor so I made a stand for it that allowed me to work on it at a comfortable height – time well spent, I think.


Romulus 7 1/4 inch gauge live steam loco boiler installed


While it was apart everything got cleaned and painted before being put back together. I had read many articles on line where other folk had built these models, every single one was different and I got loads of ideas for my own version. One thing I really wanted was to make sure it could be used for long periods, to that end I built a water tank to sit between the frames. I knew I would have plenty of water in my tender, which would double up as a driving trolley but thought the extra weight would help traction. I couldn't see a down side so that's what I did.


Romulus 7 1/4 inch gauge live steam loco motion work


I had run the motion work on compressed air and set it up so that it seemed about right and ran in forward and reverse without any problems, it was obvious that it was going to be a very powerful loco.

Next came the sheet metal work, I had already decided on a blue and found a Ford colour thst I really liked. I don't recall what the shade was called but I rather liked it and thought it looked good with the highly polished brass and copper fittings and cylinders.

I used traditional red and black for other areas, I was rather pleased with the end results.

Romulus 7 1/4 inch gauge live steam loco finished


Next job was to build the tender – this had to meet quite a few criteria – first of which was that I had to be able to drive the loco from the tender, so it had to have a comfortable seat. Secondly it had to carry enough water for a whole day's driving, space for plenty of coal was important too. The third thing was that it had to have brakes on it – big enough to stop en entire train in a hurry if needed. The model engineering society had carriages so we could give rides to the paying public – they were all braked but the loco itself needed brakes in case it was ever used on it's own. I had a good, long lever to operate them so I could pull up quickly. The loco was never going to get much speed up – maybe 10-15 mph tops but with the combined weight of me and the loco it would take a fair bit of stopping.

7 1/4 inch gauge riding trolley brake gear


The tender, just like the loco itself, had pretty basic spring suspension, it worked surprisingly well at soaking up the bigger jolts from gaps in the track. The brake mechanism was a simple lever arrangement with wooden blocks bearing on the wheels, they worked fine in test but I'm glad I never had to use them in anger.

I had an idea from the start that I wanted the tender to look a bit like a railway goods truck of some sort. I didn't build it to faithfully replicate anything in particular, I just wanted to capture the feel of it, if that makes sense.


Romulus 7 1/4 inch gauge loco with tender


I made the seat so that it hinged up and fitted two large water containers to feed the thirsty engine if she needed it. The water was fed direct in to the boiler by one of two injectors – these are super clever things that use steam pressure to inject water in to the boiler at a pressure higher than that within the boiler. They are basically witchcraft and also fussy little devils that are very hard to make and make reliable. When they do work they are brilliant, you can fit mechanical pumps too which tend to be more reliable but can only operate when the loco is in motion and can only feed water in fairly slowly, injectors are better if you are as bad a driver as I turned out to be and need to quickly refill the boiler so it doesn't melt down.

Talking of driving, these things are a lot harder than you might think, you need to constantly monitor the fire and feed it with coal. At the same time you need to keep an eye on boiler water level as if that gets too low you can destroy the boiler. Then there is the lubrication to worry about,, the pump is the square brass box on the front near the left cylinder. You have to use special steam oil, which is thick and gooey at ambient temperatures but lubricates nicely at the 110 degrees or so that the cylinders operate at. Then you have to monitor boiler pressure – you are looking for about 110 pounds per square inch. If it gets too high there are safety valves that will easily vent more pressure than the fire can produce – obviously the more heat the greater the pressure. You then have to keep your eyes open for obstructions on the track, operate the throttle and if you are carrying passengers constantly answer the same old questions from the public. The most common being 2 how fast does it go mister, where did you buy it from, how much did it cost, doesn't it go any faster.

I only ran it a few times – mostly to test the boiler and get the steam certificate for it.

I had intended to keep it but I needed the money to start another business so I had to sell it along with all the other models I had built or was building.


Romulus 7 1/4 inch gauge loco smoke box

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